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The novel HLA-A*01:420N allele has two changes in exon 4 leading to premature stop codon.

Complement-mediated interference is a well described phenomenon in single antigen bead (SAB) Luminex assay that leads to falsely low or negative results for anti-HLA antibody (Ab). In a context of high amount of Ab, the enrichment of the Ab around the bead can lead to complement cascade activation and deposition, thereafter impairing Ab detection. EDTA is now routinely used to circumvent this interference. In this report, we attempted to decipher the role of the phycoerythrin (PE) label conjugated to the secondary Ab in this interference. Indeed, PE is a huge molecule (240 kDa) that could participate to limiting access of the conjugate to its Ab target on the bead. To this purpose, 22 sera displaying complement interference without pre-treatment with EDTA were compared on SAB assay with three detection strategies: the recommended PE-conjugated secondary Ab (IgGPE), an Alexa Fluor 532-conjugated Ab (IgGAF) bearing a tiny 724 Da fluorochrome, and a biotinylated Ab followed by PE-conjugated streptavidin (IgGBiot). Complement interference occurred with the three detection methods, but its depth, defined by the percentage of MFI loss with neat serum, was the highest for IgGPE. Our study highlighted the partial role of the PE fluorochrome in complement interference in SAB assays.

The 2007 Banff working classification of skin-containing Tissue Allograft Pathology addressed only acute T cell-mediated rejection in skin. We report the longitudinal long-term histological follow-up of six face transplant recipients, focusing on chronic and mucosal rejection. We identified three patterns suggestive of chronic rejection (lichen planus-like, vitiligo-like and scleroderma-like). Four patients presented lichen planus-like and vitiligo-like chronic rejection at 52 ± 17 months posttransplant with severe concomitant acute T cell-mediated rejection. After lichen planus-like rejection, two patients developed scleroderma-like alterations. Graft vasculopathy with C4d deposits and de novo DSA led to subsequent graft loss in one patient. Chronic active rejection was frequent and similar patterns were noted in mucosae. Concordance between 124 paired skin and mucosal biopsies acute rejection grades was low (κ = 0.2, p = .005) but most grade 0/I mucosal rejections were associated with grade 0/I skin rejections. We defined discordant (grade≥II mucosal rejection and grade 0/I skin rejection) (n = 55 [70%]) and concordant (grade≥II rejection in both biopsies) groups. Mucosal biopsies of the discordant group displayed lower intra-epithelial GranzymeB/FoxP3 ratios suggesting a less aggressive phenotype (p = .08). The grading system for acute rejection in mucosa may require phenotyping. Whether discordant infiltrates reflect a latent allo-immune reaction leading to chronic rejection remains an open question.

The novel allele B*08:304 differs from B*08:01:01:01 by one nucleotide substitution in exon 2. This article is protected by copyright. All rights reserved.

The new HLA-DRB1*15:213 allele results from one nucleotide substitution in exon 3 of HLA-DRB1*15:02:01. This article is protected by copyright. All rights reserved.

Daratumumab, a humanized anti-CD38 monoclonal antibody, has demonstrated anti-plasma cell activity alone and in combination with other drugs in multiple myeloma (MM) and in light chain amyloidosis (AL). Allogenic anti-Human leukocyte antigen (HLA) antibodies are frequently encountered in patients awaiting kidney transplantation, complicating the access to a compatible transplant and represent a major risk factor of humoral rejection. Durably removing the antibodies or eliminating the producing cells is an objective that is currently out of reach. The objectives of our study were to evaluate the frequency of anti-HLA antibodies in MM and AL patients, and to determine the effect of daratumumab on them. Eligible patients with diagnosed MM or AL were selected (n = 182), among whom 84 had anti HLA antibodies (46%). Forty-nine patients (45 MM and 4 AL) were retrospectively included. Patients were treated with a combination of an alkylating agent, an immunomodulatory imide drug (IMiD), a Proteasome inhibitor, with (n = 22) or without (n = 22) daratumumab. Five patients received daratumumab alone. Treatment with daratumumab lowered anti-HLA antibodies in 85% (23/27) of cases including complete loss in 56% of cases (15/27) compared to 77% (17/22) and 45% (10/22) respectively, p = 0.8. This study couldn’t find a statistic impact of daratumumab to lower HLA antibody in this cohort. The association with chemotherapy could be an important bias and this hypothesis will be evaluated in ongoing studies enrolling patients undergoing kidney transplantation.

The novel allele HLA-C*17:64Q differs from HLA-C*17:01:01:02 by insertion of a Lysine in exon 2.

International audience; After heart transplant, adding everolimus (EVL) to standard immunosuppressive regimen mostly relies on converting calcineurin inhibitors (CNIs) into EVL. The aim of this study was to describe the effects of combining low-dose EVL and CNIs in maintenance immunosuppression regimen (quadritherapy) and compare it with standard tritherapy associating standard-dose CNIs, mycophenolate mofetil, and corticosteroids. In the 3-year registry cohort of heart transplanted patients, those who received quadritherapy were compared with those who received tritherapy. EVL was added after 3 months posttransplant. Three analyses were performed to control for confounders: propensity score matching, multivariable survival, and inverse probability score weighting analyses. Among 213 patients who were included (75 with quadritherapy), propensity score matching selected 64 unique pairs of patients with similar characteristics. In the matched cohort (n = 128), quadritherapy was associated with fewer deaths (3 [4.7%] vs 17 [21.9%], P = .007) and biopsy-proven acute rejections (15 [23.4%] vs 31 [48.4%], P = .002). These results were confirmed in the overall cohort (n = 213), after multivariable and inverse probability score weighting analyses. Renal function and donor-specific HLA-antibodies remained similar in both groups. Low-dose combination quadritherapy was associated with fewer deaths and rejections, compared with standard immunosuppression tritherapy.

Eukaryote initiation factor 2 subunit β (eIF2β) plays a crucial role in regulation protein synthesis, which mediates the interaction of eIF2 with mRNA. eIF2β contains evolutionarily conserved polylysine stretches in amino-terminal region and a zinc finger motif in the carboxy-terminus.The gene eIF2β was cloned under tetracycline transcription control and the polylysine stretches were deleted by site-directed mutagenesis (eIF2βΔ3K). The plasmid was transfected into HEK 293 TetR cells. These cells were analyzed for their proliferative and translation capacities as well as cell death rate. Experiments were performed using gene reporter assays, western blotting, flow cytometry, cell sorting, cell proliferation assays and confocal immunofluorescence.eIF2βΔ3K affected negatively the protein synthesis, cell proliferation and cell survival causing G2 cell cycle arrest and increased cell death, acting in a negative dominant manner against the native protein. Polylysine stretches are also essential for eIF2β translocated from the cytoplasm to the nucleus, accumulating in the nucleolus and eIF2βΔ3K did not make this translocation.eIF2β is involved in the protein synthesis process and should act in nuclear processes as well. eIF2βΔ3K reduces cell proliferation and causes cell death. Since translation control is essential for normal cell function and survival, the development of drugs or molecules that inhibit translation has become of great interest in the scenario of proliferative disorders. In conclusion, our results suggest the dominant negative eIF2βΔ3K as a therapeutic strategy for the treatment of proliferative disorders and that eIF2β polylysine stretch domains are promising targets for this.

Natural killer cells are the first lymphocyte subset to reconstitute, and play a major role in early immunity after allogeneic hematopoietic stem cell transplantation. Cells expressing the activating receptor NKG2C seem crucial in the resolution of cytomegalovirus episodes, even in the absence of T cells. We prospectively investigated natural killer-cell reconstitution in a cohort of 439 adult recipients who underwent non-T-cell-depleted allogeneic hematopoietic stem cell transplantation between 2005 and 2012. Freshly collected blood samples were analyzed 3, 6, 12 and 24 months after transplantation. Data were studied with respect to conditioning regimen, source of stem cells, underlying disease, occurrence of graft-versus-host disease, and profiles of cytomegalovirus reactivation. In multivariate analysis we found that the absolute numbers of CD56(bright) natural killer cells at month 3 were significantly higher after myeloablative conditioning than after reduced intensity conditioning. Acute graft-versus-host disease impaired reconstitution of total and CD56(dim) natural killer cells at month 3. In contrast, high natural killer cell count at month 3 was associated with a lower incidence of chronic graft-versus-host disease, independently of a previous episode of acute graft-versus-host disease and stem cell source. NKG2C(+)CD56(dim) and total natural killer cell counts at month 3 were lower in patients with reactivation of cytomegalovirus between month 0 and month 3, but expanded greatly afterwards. These cells were also less numerous in patients who experienced later cytomegalovirus reactivation between month 3 and month 6. Our results advocate a direct role of NKG2C-expressing natural killer cells in the early control of cytomegalovirus reactivation after allogeneic hematopoietic stem cell transplantation.

Previous studies on regulatory T-cell (Treg) reconstitution after allogeneic hematopoietic SCT (HSCT) have suggested that, within the GVHD process, imbalance between effector T cells and Tregs may be more important than the absolute numbers of circulating Tregs. No study has analyzed naive vs memory Treg reconstitution in a longitudinal cohort with large numbers of patients. The reconstitution of total and subsets of Treg was prospectively analyzed by flow cytometry in 185 consecutive recipients at 3, 6, 12 and 24 months after allogeneic HSCT. The levels of total, naive and memory Tregs increased, mainly within the memory subset, but remained lower than healthy controls up to 2 years after transplantation. Reduced-intensity conditioning and peripheral blood (PBSC) as the source of stem cells were associated with better 3-month reconstitution. In multivariate analysis, PBSC, recipient age ⩽25 and no anti-thymoglobulin in the conditioning regimen were associated with a better Treg reconstitution. Naive Treg long-term reconstitution was mainly influenced by recipient age. Whereas prior acute GVHD impaired Treg reconstitution, Treg subsets (absolute numbers and frequencies relative to CD4(+) T-cell subsets) at 3, 6 and 12 months after HSCT were not associated with the occurrence of a later episode of chronic GVHD.

Whether the efficacy of lenalidomide in the treatment of multiple myeloma (MM) is due to direct tumor toxicity only or to additional immunomodulatory effects is unclear. We studied the effect of lenalidomide treatment on T-cell immune reconstitution in patients with MM who had undergone autologous peripheral blood stem cell transplant (ASCT). Twenty-nine newly diagnosed patients with MM received induction therapy followed by high-dose melphalan and ASCT. After ASCT, 11 patients received lenalidomide consolidation therapy for 2 months followed by maintenance therapy until disease progression. The remaining 18 patients received no treatment. Serial analysis of thymic output, as given by numbers of T-cell receptor excision circles (sjTRECs), and T-cell phenotyping was performed until 18 months post-ASCT. Lenalidomide impaired long-term thymic T-cell reconstitution, decreased CD4 + and CD8 + CD45RA + CCR7 - effector-terminal T-cell absolute counts and increased CD4 + CD25 + CD127 - /low regulatory T-cells. Lenalidomide consolidation and long-term maintenance therapy, administered post-ASCT, may have a potentially negative impact on immune surveillance.

Current strategies to improve graft outcome following kidney transplantation consider information at the human leukocyte antigen (HLA) loci. Cell surface antigens, in addition to HLA, may serve as the stimuli as well as the targets for the anti-allograft immune response and influence long-term graft outcomes. We therefore performed exome sequencing of DNA from kidney graft recipients and their living donors and estimated all possible cell surface antigens mismatches for a given donor/recipient pair by computing the number of amino acid mismatches in trans-membrane proteins. We designated this tally as the allogenomics mismatch score (AMS). We examined the association between the AMS and post-transplant estimated glomerular filtration rate (eGFR) using mixed models, considering transplants from three independent cohorts (a total of 53 donor-recipient pairs, 106 exomes, and 239 eGFR measurements). We found that the AMS has a significant effect on eGFR (mixed model, effect size across the entire range of the score: -19.4 [-37.7, -1.1], P = 0.0042, χ2 = 8.1919, d.f. = 1) that is independent of the HLA-A, B, DR matching, donor age, and time post-transplantation. The AMS effect is consistent across the three independent cohorts studied and similar to the strong effect size of donor age. Taken together, these results show that the AMS, a novel tool to quantify amino acid mismatches in trans-membrane proteins in individual donor/recipient pair, is a strong, robust predictor of long-term graft function in kidney transplant recipients., Author Summary The article describes a new concept to help match donor organs to recipients for kidney transplantation. The concept relies on the ability to measure the individual DNA of potential donors and recipients. When the data about genomes (i.e., DNA) of possible donors and recipients are available, the article describes how data can be computationally compared to identify differences in these genomes and quantify the possible future impact of these differences on the functioning of the graft. The concept presented in the article determines a score for each pair of possible donor and recipient. This score is called the allogenomics mismatch score. The study tested the ability of this score to predict graft function (the ability of the graft to filter blood) in the recipient several years after transplantation surgery. The study found that, in three small sets of patients tested, the score is a strong predictor of graft function. Prior studies often assumed that only a small number of locations in the genome were most likely to have an impact on graft function, while this study found initial evidence that differences across DNA that code for a large number of proteins can have a combined impact on graft function.

Kidney transplantation is the most successful treatment option for patients with end-stage renal disease, and chronic antibody-mediated rejection is the principal cause of allograft loss. Predictive factors for chronic rejection include high levels of HLA alloantibodies (particularly HLA class II) and activation of graft endothelial cells (ECs). The mechanistic basis for this association is unresolved. We used an experimental model of HLA-DR antibody stimulation of microvascular ECs to examine the mechanisms underlying the association between HLA class II antibodies, EC activation and allograft damage. Activation of ECs with the F(Ab')2 fragment of HLA-DR antibody led to phosphorylation of Akt, ERK and MEK and increased IL-6 production by ECs cocultured with allogeneic peripheral blood mononuclear cells (PBMCs) in an Akt-dependent manner. We previously showed that HLA-DR-expressing ECs induce polarization of Th17 and FoxP3(bright) regulatory T cell (Treg) subsets. Preactivation of ECs with anti-HLA-DR antibody redirected EC allogenicity toward a proinflammatory response by decreasing amplification of functional Treg and by further increasing IL-6-dependent Th17 expansion. Alloimmunized patient serum containing relevant HLA-DR alloantibodies selectively bound and increased EC secretion of IL-6 in cocultures with PBMCs. These data contribute to understanding of potential mechanisms of antibody-mediated endothelial damage independent of complement activation and FcR-expressing effector cells.

Background Due to increased rates of secondary solid organ cancer in patients with severe aplastic anemia who received an irradiation-based conditioning regimen, we decided some years ago to use the combination of cyclophosphamide and antithymocyte globulin. We report the long-term follow up of patients who underwent hematopoietic stem cell transplantation from an HLA-matched sibling donor after this conditioning regimen.Design and Methods We analyzed 61 consecutive patients transplanted from June 1991 to February 2010, following conditioning with cyclophosphamide (200 mg/kg) and antithymocyte globulin (2.5 mg/kg/day × 5 days).Results Median age was 21 years (range 4–43); 41 of the 61 patients were adults. Median duration of the disease before hematopoietic stem cell transplantation was 93 days. All but 2 patients received bone marrow as the source of stem cells and all but 2 engrafted. Cumulative incidence of acute grade II–IV graft-versus-host disease was 23% (95%CI 13–34) and 18 developed chronic graft-versus-host disease (cumulative incidence 32% at 72 months, 95% CI 20–46). In multivariate analysis, a higher number of infused CD3 cells was associated with an increased risk of developing chronic graft-versus-host disease (P=0.017). With a median follow up of 73 months (range 8–233), the estimated 6-year overall survival was 87% (95% CI 78–97). At 72 months, the cumulative incidence of avascular necrosis was 21% and 12 patients presented with endocrine dysfunction (cumulative incidence of 19%). Only one patient developed a secondary malignancy (Hodgkin’s lymphoma) during follow up.Conclusions Cyclophosphamide and antithymocyte globulin is an effective conditioning regimen for patients with severe aplastic anemia and is associated with low treatment-related mortality. Long-term complications include avascular necrosis and endocrine dysfunction.

The DEFI study has collected clinical data and biological specimens from kindreds with CVID. Patients with demonstrated parental consanguinity (cCVID group) were compared to patients without parental consanguinity (ncCVID). A total of 24 of the 436 patients with CVID had consanguineous parents. Age at first symptoms and age at diagnosis were comparable in the two groups. Some complications were more frequent in cCVID patients: splenomegaly (62.5% vs. 29%; p = 0.001), granulomatous disease (29% vs. 12%; p = 0.02), and bronchiectasis (58% vs. 29%; p = 0.003). A high incidence of opportunistic infections was also observed in this population (29% vs. 5%; p < 0.001). Distribution of B-cell subsets were similar in the two groups. Naive CD4+ T cells were decreased in cCVID patients (15% vs. 28%; p < 0.001), while activated CD4 + CD95+ (88% vs. 74%; p = 0.002) and CD8 + HLA-DR + T cells (47% vs. 31%; p < 0.001) were increased in these patients when compared to ncCVID patients. Parental consanguinity is associated with an increased risk of developing severe clinical complications in patients with CVID. Most of these patients presented with severe T-cell abnormalities and should be considered with a diagnosis of late-onset combined immune deficiency (LOCID). Systematic investigation for parental consanguinity in patients with CVID provides useful information for specific clinical care and genetic screening.

The incidence of herpes zoster remains high in HIV-infected patients despite the use of combined antiretroviral therapy (cART). We wished to assess varicella-zoster virus (VZV)-specific cell-mediated immune (CMI) responses in HIV-infected adults on cART. VZV-specific CMI responses were assessed using lymphocyte proliferative responses, cytokine production (IL-2, TNF-α, and IFN-γ), and interferon-γ ELISPOT assays in 103 HIV-infected adults and 30 healthy controls. HIV-infected patients were analyzed according to their current and nadir CD4 cell count and their use of cART. A multivariate analysis was performed to identify factors associated with VZV-specific CMI responses. HIV-infected patients had lower VZV-specific CMI responses than healthy controls. Patients with a CD4 T cell count100/μL had almost no detectable responses whereas those with a current CD4 T cell count300/μL and suppressed viral replication on cART had responses similar to those of healthy controls. In multivariate analysis, factors significantly associated with VZV-specific CMI responses were the absence of a previous AIDS-defining event and higher CD4 cell counts, in particular central and effector memory CD4 T cell counts. HIV-infected patients with a history of AIDS or low CD4 cell counts have impaired VZV-specific CMI responses, and remain at risk for herpes zoster.

Double unrelated cord blood transplant (dUCBT) has been used to circumvent cell dose limitation of single UCBT; however, few data are available describing outcomes, infectious disease, and immune recovery. We analyzed 35 consecutive dUCBT recipients with high-risk malignant disorders (n=21) and bone marrow failure syndromes (n=14). Median follow-up was 32 months. Conditioning regimen was myeloablative in 14 and reduced intensity in 21 patients. Median infused nucleated cell dose was 4 × 10(7) /kg. Median time to absolute neutrophil count >0.5 × 10(9) /L was 25 days. Cumulative incidence (CI) of acute grade II-IV graft-versus-host disease was 47%. Estimated overall survival at 2 years was 48%. CI of first viral infections at 1 year was 92%. We observed 49 viral infections in 30 patients, 34 bacterial infections in 19 patients, and 16 fungal or parasitic infections in 12 patients. Lymphocyte subset analyses were performed at 3, 6, 9, and >12 months after dUCBT. Decreased T-cell and B-cell counts with expansion of natural killer cells were observed until 9 months post transplantation. Recovery of thymopoiesis measured by T-cell receptor excision circles was impaired until 9 months after dUCBT, when the appearance of new thymic precursors was observed. Delayed immune recovery and high incidence of infectious complications were observed after dUCBT in patients with high-risk hematological diseases.

Common variable immunodeficiency (CVID) is a heterogeneous disorder characterized by recurrent infections and defective immunoglobulin production.The DEFI French national prospective study investigated peripheral T-cell and B-cell compartments in 313 CVID patients grouped according to their clinical phenotype, using flow cytometry.In patients developing infection only (IO), the main B-cell or T-cell abnormalities were a defect in switched memory B cells and a decrease in naive CD4(+) T cells associated with an increase in CD4(+)CD95(+) cells. These abnormalities were more pronounced in patients developing lymphoproliferation (LP), autoimmune cytopenia (AC), or chronic enteropathy (CE). Moreover, LP and AC patients presented an increase in CD21(low) B cells and CD4(+)HLA-DR(+) T cells and a decrease in regulatory T cells.In these large series of CVID patients, the major abnormalities of the B-cell and T-cell compartments, although a hallmark of CVID, were only observed in half of the IO patients and were more frequent and severe in patients with additional lymphoproliferative, autoimmune, and digestive complications.

BACKGROUND Common variable immunodeficiency (CVID) is a primary immune deficiency defined by defective antibody production. In most series, a small proportion of patients present with opportunistic infections (OIs). METHODS The French DEFI study has enrolled patients with primary hypogammaglobulinemia and allows a detailed clinical and immunologic description of patients with previous OIs and/or at risk for OIs. RESULTS Among 313 patients with CVID, 28 patients (8.9%) presented with late-onset combined immune deficiency (LOCID), defined by the occurrence of an OI and/or a CD4(+) T cell count

OBJECTIVE To study the kinetics and identify factors associated with Toxoplasma-specific immune responses in patients with AIDS starting antiretroviral therapy. METHODS A prospective study of 38 HIV-infected patients seropositive for Toxoplasma who started antiretroviral therapy with CD4 T cells less than 200 cells/microl. T-cell and B-cell phenotypes, anti-Toxoplasma antibodies titers, Th-1 and Th-2 cytokine production and lymphocyte proliferative responses (LPRs) to Toxoplasma were assessed over 12 months. RESULTS Median CD4 cell count increased from 122 cells/microl at baseline to 260 cells/microl at 12 months, and the incidence of a positive LPR from 18.4 to 70.5%. A Toxoplasma IgG titer more than 150 IU/ml was the only baseline variable associated with a positive LPR (hazard ratio: 4.6, P = 0.003). Among time-dependent covariates, the number of effector memory (CD45RA-CCR7-) CD4 T cells was associated with a positive LPR (P < 0.02) and the number of terminally differentiated (CD45RA+CCR7-) CD8 T cells was associated with in-vitro production of gamma-IFN (P < 0.008). CONCLUSION Among patients with low CD4 cell counts, high anti-Toxoplasma IgG titers were associated with LPR to Toxoplasma antigen. After starting antiretroviral therapy, the number of effector memory CD4 T cells and terminally differentiated CD8 T cells were associated with the restoration of Toxoplasma LPR and gamma-IFN production, respectively.

International audience; Erosive oral lichen planus (OLP) is a chronic, disabling mucocutaneous dysimmune rare disease characterized by mucosal inflammatory erosive lesions with pathological evidence for a marked CD8+ cytotoxic T-lymphocyte (CTL) infiltration. However, the specificity of lesional CTL in OLP has never been analyzed. To investigate the molecular mechanisms underlying dysregulation of T-cell immune responses in patients with OLP, we studied the diversity and antigen specificity of the TCR expressed by CD8+ T cells using dextramer staining, spectratyping, and TCR sequencing in 10 OLP patients undergoing extracorporeal photochemotherapy. Expansions of TCRVβ3-bearing CD8+ T cells were found in peripheral blood and in lesional tissues of OLP patients. Spectratyping and sequencing studies identified specific clonotypes in each patient. These expansions were enriched with human papillomavirus 16 (HPV16)-specific CD8+ T cells in HLA-A*0201+ patients as shown by their immune recognition of the E711-20 immunodominant epitope. Under treatment with extracorporeal photochemotherapy, clonotypic CD8+ T-cell expansions decreased in parallel with clinical remission. Altogether, these data establish a link between HPV infection and OLP pathogenesis by identifying a massive clonal expansion of CD8+ T cells with increased frequency of HPV 16-specific CD8+ T cells in OLP patients.

BACKGROUND Local inflammation is a potential cause of humoral alloimmune responses in renal transplantation, and de novo donor-specific anti-human leucocyte antigen antibodies (dnDSAs) have been associated with a history of acute rejection. METHODS We investigated the frequencies and consequences of dnDSAs after a first episode of acute T-cell-mediated rejection (index TCMR) in previously unsensitized kidney transplant recipients. RESULTS Of the 1,054 patients who underwent kidney transplantation between September 2004 and December 2010 at our center, we identified 75 unsensitized patients with at least one TCMR. Index TCMRs were diagnosed 4.4 ± 6.8 months after transplantation. The dnDSAs were assessed using the highly sensitive single-antigen human leukocyte antigen bead assay 5.1 ± 3.9 months after the index TCMR and were detected in 16 patients (21%). Patients who developed dnDSAs were more likely to have experienced pre-transplant sensitizing events and were indistinguishable in their clinical, biologic, and histologic variables at the time of index TCMR, although the tubulitis scores tended to be higher (P = 0.079). These patients experienced a significantly higher incidence of subsequent antibody-mediated rejection episodes (P < 0.001), but reduced death-censored graft survival was not observed after a median follow-up of 5.5 years post-transplantation. Follow-up biopsies revealed increased antibody-mediated changes with significantly higher glomerulitis scores and numerically higher C4d staining scores. CONCLUSION Monitoring anti-human leukocyte antigen antibodies after cellular rejection may be useful, especially among patients with a history of pretransplant exposure to alloantigens, to predict subsequent humoral events and their consequences.

Objective To analyze hematopoietic and immune reconstitution after autologous hematopoietic stem cell transplantation (HSCT) in 7 patients with systemic sclerosis (SSc). Methods Two groups of patients were retrospectively constituted according to whether they had a favorable clinical response (group A; n = 4) or no response or a relapse of disease (group B; n = 3) after HSCT. Immune reconstitution was analyzed every 3 months using lymphocyte immunophenotyping, α/β T cell receptor (TCR) diversity analysis, and ex vivo thymic function analysis by quantification of TCR rearrangement excision circles (TRECs). Results Patients had similar characteristics at study entry, except for a lower modified Rodnan skin thickness score (P = 0.03) and a lower Health Assessment Questionnaire score (P = 0.05) in group A than in group B. The number of reinjected cells and the time to hematopoietic reconstitution were similar in both groups. The absolute numbers of CD19+ and CD20+ B cells were lower in group A than in normal controls (P < 0.05) and within the normal range in group B. Absolute numbers of T and natural killer lymphocytes were normal before HSCT. Numbers of CD3+ cells remained low thereafter. Numbers of CD8+ cells were back to normal 3 months after HSCT in both groups. B cell counts were low until 6 months after HSCT in group A and stayed in the normal range in group B. The CD3+ defect was sustained in group A, with an opposite trend and a faster CD4+ reconstitution profile in group B. The T cell repertoire was skewed before and until 1 year after HSCT, with shared expansions before and after transplant in a given individual. TREC values correlated negatively with C-reactive protein levels (rs = −0.41, P = 0.001) and positively with CD19+ (rs = 0.35, P = 0.001) and CD20+ (rs = 0.34, P = 0.002) lymphocyte counts. Conclusion B and T lymphocyte populations remained disturbed for at least 1 year after HSCT in SSc patients, which may reflect the persistence of an underlying disease mechanism.

BACKGROUND Activating anti-angiotensin type 1 receptor antibodies (AT1R-AA) have been described in patients with systemic scleroderma, an auto-immune disorder with clinical fibrotic features. Chronic graft-versus-host disease (cGvHD) after hematopoietic stem cell transplantation may have clinical fibrotic features, whose pathogenesis may be similar with systemic sclerosis. OBJECTIVE To evaluate the presence of AT1R-AA and their association with clinical and biological symptoms in cGvHD patients. MATERIAL AND METHODS Sera from 87 patients including 45 extensive cGvHD and 42 hematopoietic stem cell transplantation patients without cGvHD were retrospectively analyzed for the presence of AT1R-AA using an enzymatic immunoassay. RESULTS The frequency of AT1R-AA was significantly increased (odds ratio [OR]=3.4, P=0.04) in the cGvHD group (24.4%) compared with the non-cGvHD group (7.1%). In the cGvHD group the positivity of AT1R-AA was significantly associated with: i/ the presence of antinuclear antibodies (OR=5.9, P=0.04) ii/ a more severe global and organ-specific cGvHD scoring (P

To evaluate the long-term immune reconstitution after allogeneic haematopoietic stem cell transplantation (SCT), we prospectively screened standard immune parameters in a series of 105 patients, at a median time of 15 months after SCT. Analysing lymphoid phenotypes, in vitro immune functions and immunoglobulin levels, we found that, more than 1 year post SCT, cellular and humoral immunity was still altered in a significant number of patients. CD4+ T cells were < 200/microl in one third of patients, and the CD4/CD8 ratio was still reversed in 78% of patients. Almost all patients showed positive T-cell responses against mitogens, but antigen-specific proliferation assays identified 20% to 80% of non-responders. B-cell counts were reconstituted in 61% of the patients, but levels of total immunoglobulins were still low in 59%. In multivariate analyses, human leucocyte antigen (HLA) disparity between donor and recipient and chronic graft-versus-host disease were the leading causes affecting immune reconstitution. Interestingly, cytomegalovirus (CMV) infections were strongly associated with normal CD8+ T-cell counts. Studying the impact of impaired immune reconstitution on the rate of infections occurring in the 6 years following screening, we identified three parameters (low B-cell count, inverted CD4/CD8 ratio, and negative response to tetanus toxin) as significant risk factors for developing such late infections.

Mismatched unrelated donor (MMUD) or umbilical cord blood (UCB) can be chosen as alternative donors for allogeneic stem cell transplantation but might be associated with long-lasting immune deficiency. Sixty-six patients who underwent a first transplantation from either UCB (n = 30) or 9/10 MMUD (n = 36) and who survived beyond 3 months were evaluated. Immune reconstitution was prospectively assessed at sequential time points after transplantation. NK, B, CD4(+), and CD8(+) T cells and their naïve and memory subsets, as well as regulatory T cells (Treg), were studied. Detailed analyses on infections occurring after 3 months were also assessed. The 18-month cumulative incidences of infection-related death were 8% and 3%, and of infections were 72% and 57% after MMUD and UCB transplantation, respectively. Rates of infection per 12 patient-month were roughly 2 overall (1 for bacterial, .9 for viral, and .3 for fungal infections). Memory, naïve CD4(+) and CD8(+)T cells, naïve B cells, and Treg cells reconstitution between the 2 sources were roughly similar. Absolute CD4(+)T cells hardly reached 500 per μL by 1 year after transplantation and most B cells were of naïve phenotype. Correlations between immune reconstitution and infection were then performed by multivariate analyses. Low CD4(+) and high CD8(+)T cells absolute counts at 3 months were linked to increased risks of overall and viral (but not bacterial) infections. When assessing for the naïve/memory phenotypes at 3 months among the CD4(+) T cell compartment, higher percentages of memory subsets were protective against late infections. Central memory CD4(+)T cells protected against overall and bacterial infections; late effector memory CD4(+)T cells protected against overall, bacterial, and viral infections. To the contrary, high percentage of effector- and late effector-memory subsets at 3 months among the CD8(+) T cell compartment predicted higher risks for viral infections. Patients who underwent transplantation from alternative donors represent a population with very high risk of infection. Detailed phenotypic analysis of immune reconstitution may help to evaluate infection risk and to adjust infection prophylaxis.

The detection of preformed donor-specific alloantibodies (DSA) with multiplex-bead arrays has led to the common observation that individuals without a history of pregnancy, transfusion or transplantation can have circulating anti-HLA antibodies of unknown etiology. We retrospectively analyzed the risk of antibody-mediated rejection (AMR) and graft outcome in 41 kidney transplant recipients with DSA of unknown etiology (DSA cause-unk) at the time of transplantation. Twenty-one patients received a posttransplantation desensitization protocol, and 20 received standard immunosuppressive therapy. The mean number of DSA was 1.4 ± 0.8, ranging from 1 to 5. Complement-dependent cytotoxicity crossmatches were negative for all the patients. Flow cytometry crossmatches were positive in 47.6% of cases. The incidence of acute AMR was 14.6% at 1 year, regardless of the immunosuppressive regimen. No patients experienced graft loss following AMR. At month 12, across the entire population of patients with DSA cause-unk, the outcomes were favorable: the measured glomerular filtration rate was 63.8 ± 16.4 mL/min/1.73 m(2), the screening biopsies showed low frequencies of microvascular inflammation and no transplant glomerulopathy, and graft and patient survival were 100%. In conclusion, patients with DSA cause-unk are able to mount AMR but have favorable 1-year outcomes.

BACKGROUND Preemptive rituximab (R) treatment decreases the incidence of Epstein-Barr virus (EBV) posttransplantation lymphoproliferative disease, but the extent of immune deficiency related to R in patients who received allogeneic hematopoietic stem-cell transplantation is unclear. The aim of our study was to evaluate the incidence of late infections and immune reconstitution after preemptive R treatment of EBV infection. METHODS Seventy-eight patients receiving preemptive R between January 2005 and January 2010 were studied. Fifty-two of them could be matched with controls (not receiving R) according to administration of antithymoglobulin, stem-cell source and donor type, age and grade of acute graft-versus-host disease. RESULTS Among the 78 patients with EBV reactivation treated with R, the 36-month cumulative incidence of bacterial, viral, and fungal infections was 64%, 59%, and 23%, respectively. When compared with controls, bacterial infection incidence was significantly higher in R patients (55% vs. 35%), and a slower reconstitution of B cells was observed. R patients had modest but not significantly higher nonrelapse mortality (35% vs. 15%) than controls. CONCLUSION R has dramatically decreased risks of posttransplantation lymphoproliferative disease but is followed by a prolonged and profound B-cell deficiency associated with an excess risk of bacterial infection and higher mortality. R should be given with caution, and immunoglobulin replacement should be provided to limit these excess risks.

Immune reconstitution was analyzed in 140 consecutive patients who were 2-year disease-free and who underwent myeloablative allogeneic transplantation. A CD4 and CD8 defect was observed involving naive, terminally differentiated, memory and competent cells and above limits values for activated subsets. Natural killer cells normalize at six months while we observed expansion of CD19(+)/CD5(+) B cells after three months and a persisting defect of memory B cells. Chronic graft-versus-host disease did not influence significantly those parameters for CD8 subsets while the naïve and competent CD4 subsets were strongly affected. But the most profound impact of chronic graft-versus-host disease was on B-cell subsets, especially on the memory B population. The cumulative incidence of late severe infections was low (14% at four years). Using Cox's models, only low B-cell counts at 12 (P=0.02) and 24 (P=0.001) months were associated with the hazard of developing late infection, in particular if patients did not develop chronic graft-versus-host disease.

Long-term T-cell reconstitution after hematopoietic stem cell transplantation (HSCT) is dependent on patient thymic function and affected by graft-versus-host disease (GVHD). To assess the impact of acute GVHD (aGVHD) on thymic function, we followed a cohort of 93 patients who received HSCT from a human histocompatibility leukocyte antigen-identical sibling, mainly for hematologic malignancies. Thymic output was measured by signal-joint T-cell receptor excision circles (sjTREC) real-time polymerase chain reaction. Absolute sjTREC number was lower at 6 months in patients with aGVHD (P = .014), associated with lower absolute counts of naive CD4 T cells at 6 and 12 months (P = .04 and .02), and persistent abnormalities in T-cell repertoire diversity. Age and aGVHD affected thymic function independently in multivariate analysis. In patients less than 25 years of age, thymic function recovered almost totally at 1 year. As a marker of thymocyte proliferation, we quantified the βTREC generated during the T-cell receptor β-chain recombination, in a group of 20 age-matched patients. Mean βTREC level was reduced at 6 months in patients with aGVHD, indicating an impact on early thymic differentiation rather than on intrathymic proliferation. These data show that aGVHD or its treatment has a transient impact on thymic function in younger patients in the first months after HSCT.

The expansion of the cytokine-producing CD56bright NK cell subset is a main feature of lymphocyte reconstitution after allogeneic hematopoietic stem cell transplantation (HSCT). We investigated phenotypes and functions of CD56bright and CD56dim NK subsets from 43 HLA-matched non-T cell-depleted HSCT donor-recipient pairs. The early expansion of CD56bright NK cells gradually declined in the posttransplant period but still persisted for at least 1 year and was characterized by the emergence of an unusual CD56brightCD16low subset with an intermediate maturation profile. The activating receptors NKG2D and NKp46, but also the inhibitory receptor NKG2A, were overexpressed compared with donor CD56bright populations. Recipient CD56bright NK cells produced higher amounts of IFN-γ than did their respective donors and were competent for degranulation. Intracellular perforin content was increased in CD56bright NK cells as well as in T cells compared with donors. IL-15, the levels of which were increased in the posttranplant period, is a major candidate to mediate these changes. IL-15 serum levels and intracellular T cell perforin were significantly higher in recipients with acute graft-vs-host disease. Altogether, CD56bright NK cells postallogeneic HSCT exhibit peculiar phenotypic and functional properties. Functional interactions between this subset and T cells may be important in shaping the immune response after HSCT.

We report a case of primary Epstein-Barr virus infection with lung involvement occurring 1 month after bone marrow transplantation. The transplant recipient had serological test results that were negative for Epstein-Barr virus before transplantation. The virus must have been transmitted by the donor's bone marrow, which was positive for Epstein-Barr virus. The patient recovered after rituximab and corticosteroid therapy.

Thymic function is critical for immune reconstitution after hematopoietic stem cell transplantation (HSCT). We evaluated recipient thymic function before HSCT by quantifying T-cell receptor excision circles (TRECs) in pretransplantation peripheral blood lymphocytes from 102 patients who received HSCs from an HLA-identical sibling for malignant (n = 87) or nonmalignant diseases (n = 15). Median TREC value before transplantation was 257 TRECs per 150 000 CD3+ cells (range, 0-42 746). We assessed 172 TRECs per 150 000 CD3+ cells as the most discriminating TREC value for survival in a first cohort of patients (n = 62). This cut-off was validated in a second independent prospective group of 40 patients. In the 102 patients, a TREC value greater than or equal to 172 was associated with a better survival (P < .000 01), a decreased incidence of grade II-IV acute graft-versus-host disease (GVHD; P = .017), chronic GVHD (P = .023), and bacterial (P = .003) and cytomegalovirus (CMV) infection (P = .024). In a multivariate analysis, low pretransplantation TREC values were associated with a higher incidence of CMV infection (hazard ratio [HR] = 2.0, P = .06) and severe bacterial infections (HR = 2.8, P = .036). Finally, high TREC values (HR = 6.6, P = .002) and ABO compatibility (HR = 2.7, P = .02) were associated with a better survival. Therefore, recipient host thymic function assessment could be helpful in predicting HSCT outcome and identifying patients who require a close immunologic monitoring.

Aim Vascularized composite allotransplantations (VCA) provide therapeutic options for functional or esthetic damage beyond conventional surgical reconstruction. The objectives of this study were to evaluate the immunological characteristics of patients treated for third degree burns who could benefited from reconstructive transplantation by VCA and to determine their access to transplantation. Methods Serum samples of all the 29 patients treated in a single center from 2007 to 2010 for extensive burns were collected. Fifteen patients received skin allografts, 8 cryopreserved skin allografts (CPSA) and 7 glycerolized preserved skin allografts (GPSA). Anti HLA Ab and C1q binding Ab were detected by LABScreen single-antigen, (One Lambda, Canoga Park, CA), MFI cut offs were respectively 500 and 300 over background. Then cPRA representing the percentage of potential donors expected to present unacceptable mismatches was calculated. Results Among the patients, 97% had anti HLA Ab, 45% had C1q fixing Ab, 62% were considered hyperimmunized with a cPRA above 85%. The average cPRA score of the 1055 patients on the waiting list for kidney transplantation at the same time in the same region was 27.2% ± 37.3 whereas it was 64.7%± 40.8 for burned patients. The risk of being hyper immunized was 3.3 times higher for burned patients than for those on the waiting list for kidney transplantation. Multivariate analysis (stepwise backward before multiple linear regression) identified the use of CPSA (p=0.0043) and the number of previous pregnancies (p=0.0074) to be independent predictive factors for cPRA with an adjusted coefficient of determination (R 2 ) of 0.37 (p = 0.0024). Conclusions Anti-HLA alloimunization is potentially a major obstacle to VCA in extensively burned patients. To improve access to transplantation, glycerolized preserved skin allografts should be preferred to cryopreserved skin allograft for burned patients suffering extensive facial and hand injuries when possible.

Aim Detection of preformed donor specific alloantibodies (DSA) with Luminex Single Antigen assay led to the common observation that individuals without history of pregnancy, transfusion or transplantation could have “natural” anti-HLA antibodies (Ab). Methods We retrospectively analyzed the risk of antibody-mediated rejection (AMR) and graft outcome in two groups of kidney transplant recipients with “natural” DSA present at time of transplantation: 21 patients received a post-transplantation desensitization protocol and 20 patients a standard protocol. We compared them to a third group of 26 patients with preformed “non-natural” DSA within same range of MFI, treated with post-transplant desensitization. Sera from the day of transplantation were tested for class I and II DSA by Luminex LABScreen® Single Antigen (One-Lambda Inc., CA, USA), beads showing a mean fluorescence intensity (MFI) >500 were considered positive. Results Patients with natural Ab were similar regarding number of HLA mismatches, class of DSA and MFI of the immunodominant DSA (iDSA).The MFI of the natural iDSA ranged from 500 to 3267. In the “non-natural” group, the mean number of DSA per patient (1.9 ± 1.3 versus 1.4 ± 0.8 in the two natural groups, p=0.07), as well as theMFI of iDSA by selection, were similar in the patients with non-natural and natural DSA . At one year in patients with natural DSA, the incidence of acute AMR was 10.0%, whatever the immunosuppressive regimen, and was similar to that observed in patients with “non-natural” DSA (15.4%, p=0.47). In patients with natural or non-natural DSA, glomerular filtration rate was similar and screening biopsies showed a low frequency of microvascular inflamation (g+ptc > 1 in 9.1 and 13.0% of cases, respectively), and no transplant glomerulopathy. Graft and patient survival were 100% whatever the group. Conclusions In conclusion, patients with natural DSA are able to mount AMR but with a favorable one-year outcome, similar to that observed in patients with “non-natural” DSA.